Hi, How do you subset a dataframe so that you only have columns:
1. that contain one or more NAs? 2. that contain factors with greater than or equal to 32 levels? How do you remove from a dataframe columns** 3. with one or more NA's? 4. that contain factors with greater than or equal to 32 levels? ** I know how to remove columns at a basic level but I am trying to figure out a more efficient way of performing these particular tasks (my data set has 60 columns). For NA's I essentially used summary(mtcars) and manually made a note of where NA's appeared than used: mtcars1<-mtcars1[,!(names(mtcars1)%in% c("hp","wt","vs"))] I did something similar for factors with greater than x levels only I used str(mtcars) to help me identify them. BTW I know mtcars doesn't have any of these issues. I just used it as a quick reference. Dan [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.